1. Field of the Invention
The invention relates to techniques for maintaining a desired level of oil in crankcases and sumps and, more particularly, to an oil dispenser especially adapted for use with internal combustion engines.
2. Description of the Prior Art
In internal combustion engines, lubricating oil typically is stored in a crankcase or sump disposed on the underside of the engine. During the operation of the engine, oil is withdrawn from the crankcase and is pumped throughout the engine in order to cool, lubricate, and clean various moving parts. Oil thus circulated eventually is returned to the crankcase. Depending upon the age of the engine, its manner of operation, and other factors, oil eventually is consumed and the level of oil in the crankcase drops. The characteristic of internal combustion engines to consume lubricating oil requires that the operators of such engines check the level of oil in the crankcase at relatively frequent intervals.
Even if the oil level is checked regularly and oil is replenished when necessary, it is possible that too much or too little oil will be added. It is well known that internal combustion engines have an optimum oil level--if the oil level deviates from the optimum level then the rate of oil consumption increases. Accordingly, it is desirable not only to maintain a minimum quantity of oil in the crankcase under all operating conditions in order to prevent engine damage, but the quantity of oil in the crankcase should be maintained as close as possible to the optimum level for that engine. Unfortunately, the conventional technique of manually checking the oil level and replenishing oil as necessary is an ineffective way to maintain an optimum level of oil in the crankcase.
In order to address the foregoing concerns, various oil dispensers have been created for use with internal combustion engines. In general, these devices dispense oil to a crankcase or sump from an airtight container by means of gravity. Certain devices employ a single tube that provides both an oil flow and an oil level control function. Other devices employ two tubes, one for dispensing oil and one for controlling the flow of oil to be dispensed. Most oil dispensers include a control valve of some type, either manual or automatic, that permits the dispensing of oil either when the engine has been shut down or while it is operating. Representative dispensers of the type described are shown by U.S. Pat. Nos. 1,251,606, 2,671,529, 1,465,167, and others.
Although oil dispensers for internal combustion engines have been known for many years, they have not been utilized to any significant extent. One of the reasons for the lack of utilization of such devices is believed to be their expense. Particularly in the case of oil dispensers adapted for use with engines during operation, fairly sophisticated level-control apparatus is required to insure that the engine is not over-lubricated or under-lubricated. Even in less complex and expensive devices adapted to dispense oil only while the engine is inoperatively, considerations of expense and complexity have limited the utilization of such devices.